Conventionally, in lamp technology, the base of the lamp is attached to the burner by cement. Also referring to FIG. 1 of the accompanying drawings, this ceramic suspension (8) is applied between the lamp base (3) and the burner of the lamp (1). After application, this suspension needs to be dried out (at a higher temperature e.g. 150° C.) to harden it. The formulation of this suspension is critical to have the right strength and stability over the life of the lamp. In case of flawed formulation, the cement can start crumbling and the lamp will become loose at the base.
Also, the heating process to dry and harden the cement is critical for its strength and stability. In case said process is done hastily, the suspension can “boil”, leaving larger air bubbles in the hardened cement. Applying the cement is a time consuming process as one needs to prepare the mixture, apply the suspension to the base of the lamp while burner is inside the base, allow the cement to dry and also clean the spilt cement from the lamp and also clean the used tools before cement hardens.
Publication no. EP0668639 relates to a bulb socket comprising a bulb receptacle and at least one contact fitting arranged in the bulb receptacle, wherein the bulb receptacle comprises at least one support portion for supporting the contact fitting and being deflectable upon insertion/withdrawal of a bulb into/from the bulb socket. According to a second aspect of the invention, a bulb socket is provided comprising a bulb receptacle and at least one contact fitting arranged in the bulb receptacle, wherein the contact fitting comprises movable contact means movable upon insertion/withdrawal of a bulb into/from the bulb socket and extending over or through an adjacent side wall of the bulb receptacle such that the movable contact means can be bent outwardly. In this publication, the clip is used for electrical contact, and it is used in longitudinal direction.
U.S. Pat. No. 5,420,474 relates to a press sealed lamp focusably mounted in a base. A focusable lamp comprises lamp capsule, coupler, and a base. The capsule is formed with rigid leads. The capsule and coupler are further formed to allow capsule to be held in the coupler and still focused with respect to the coupler. The coupler also includes an internally projecting tab that is sufficiently near one lead that despite movement of the lead during focusing, the gap between the lead and tab may be bridged by solder to thereby electrically and mechanically fix the lamp capsule to the coupler. The coupler and second lead are further aligned and connected to a base. No cement is needed to position the lamp capsule. In this patent differently designed clip is being used inside the base with the objective of electrically connecting the burner and hence there is a risk of electrical breakdown when high voltage is used as for discharge lamps.
U.S. Pat. No. 4,630,880 relates to the tab protruding from a primary electrical contact means in a snap-in terminal for urging contact with misaligned filament wires of a wedge-base bulb. The invention improves electrical contact between the bulb and terminal and allows the terminal to be used in a socket housing made from soft vinyl material. A tab protruding from a primary electrical contact means in a snap-in terminal for urging contact with misaligned filament wires of a wedge-base bulb. The vent tube is cylindrically shaped and centrally located on wedge-base in the longitudinal axis of bulbular evacuated chamber. The centrally located cylindrically shaped vent tube separates two side wings of the wedge base. The side wings encapsulate the filament wires and also have a concave detent trough. The troughs are perpendicular to the vent tube. This patent explains the improvement of the electrical contact.
Publication no. EP0261722 relates to the electric lamp that has a lamp vessel which is fixed by means of cement in a lamp cap of synthetic material. A metal ring in contact with the cement is present in the lamp cap. As a result of this, the cement can be secured by inductive heating of the metal ring. The lamp cap has a spacer member, for example in the form of projections on the inner side of the lamp cap, by which the metal ring is separated from the lamp cap. This publication uses cement in this design as a metal ring is placed inside the cement to aid curing it (inductively heated).
U.S. Pat. No. 6,469,428 relates to the lamp bulb made from glass which is sealed at one end by a pinch. A base is fastened on the pinch by means of a metal spring. The base has a holder loosely adapted to the pinch. The metal spring is bent in a U-shaped fashion and comprises a base part and two limbs which embrace the pinch, the fastening of the base being accomplished by virtue of the fact that one limb is aligned essentially parallel to the longitudinal axis, but simultaneously has a transverse extent 5 to 20% larger than the transverse extent of the holder of base. However, said patent discloses a U-shaped clip that fits around the base of a press seal to hold the bulb in the base wherein one of the limbs has lateral ends which is rolled in. The burner has two lead wires and the clip is attached between them. This clip is mounted over the bottom of the burner. This design cannot be used for lamps with a return lead beside the burner as in the present disclosure.
The said EP patent requires, inter alia, a U-shaped metal spring comprising a based part and two arms, where the arms embrace the pinch of a bulb with at least one of the arms being aligned parallel to the longitudinal axis of the bulb, and where the base of the metal spring runs centrally between the two supply leads of the bulb with at least 3 mm clearance from each supply lead.
Also in the mechanical arrangement, there is possibility of a short circuit between the leads passing by the metal clip as shown in FIG. 1 of said EP patent. If the positioning is not good, the burner can be out of line because it is only held on the bottom in the base and the positioning in horizontal or longitudinal direction in the base is not under control.
Thus, the conventional system does not provide proper alignment of the lamp in the center of the base. Also, the conventional clips cannot be used for lamps where position of the burner is more critical e.g. photo-optic lamps. Hence there exists a need of a mounting system for mounting and aligning the burner in the center of the base, which will be cost-effective, efficient and time saving.
With all the above discussed restrictions or limitations, it is essential to have a cement less base for the lamp.